Ecological restoration on former agricultural soils: Feasibility of in situ phosphate fixation as an alternative to top soil removal

2011 ◽  
Vol 37 (11) ◽  
pp. 1620-1629 ◽  
Author(s):  
Jeroen J.M. Geurts ◽  
Paul A.G. van de Wouw ◽  
Alfons J.P. Smolders ◽  
Jan G.M. Roelofs ◽  
Leon P.M. Lamers
1999 ◽  
Vol 30 (3) ◽  
pp. 177-190 ◽  
Author(s):  
Per Atle Olsen

The hydraulic conductivity in structured soils is known to increase drastically when approaching saturation. Tension infiltration allows in situ infiltration of water at predetermined matric potentials, thus allowing exploration of the hydraulic properties near saturation. In this study, the near saturated (ψ≥-0.15 m) hydraulic conductivity was estimated both in the top- and sub-soil of three Norwegian soils. A priory analysis of estimation errors due to measurement uncertainties was conducted. In order to facilitate the comparison between soils and depths, scaling analysis was applied. It was found that the increase in hydraulic conductivity with increasing matric potentials (increasing water content) was steeper in the sub-soil than in the top-soil. The estimated field saturated hydraulic conductivity was compared with laboratory measurements of the saturated hydraulic conductivity. The geometric means of the laboratory measurements was in the same order of magnitude as the field estimates. The variability of the field estimates of the hydraulic conductivity from one of the soils was also assessed. The variability of the field estimates was generally smaller than the laboratory measurements of the saturated hydraulic conductivity.


2014 ◽  
pp. 75-80
Author(s):  
Károly Bakos ◽  
Attila Dobos ◽  
János Nagy

In this article we are presenting the methodology applied to analyse and interpret the topsoil surface reflectance parameters of multiple samples collected in the Mugello valley area in northern Italy in October 2012. The main aim of the whole project was to discover geomorphological behaviour and situation of the area ino order to improve potential for correct dating of certain archaeological artefacts found in the nearby areas. One of the crucial problem researchers are facing in the area is the lack of understanding of the underlying geological and geomorphological processes that were describing and characterizing the area and that played important role not only in the current geography and landscape formation but also in the transportation of various sediments and artefacts. In this particular research the main aim is to examine the possibility of developing a quick way to assess low level properties of the soil using hand held spectrometer and rapid analysis of cross-section using in situ measurement techniques. In this work we collected over 2000 individual samples of topsoil surface reflectance properties that we organized into a spectral library. This library is then to be used to describe physical and chemical processes in the soil. To support the analysis results were compared to analysis results from different kind of assessments in the same area. Our results show a great potential of application of hand held imaging spectrometer in soil property analysis based on the top soil surface reflectance parameters.


2018 ◽  
Vol 29 (3) ◽  
pp. 485-494 ◽  
Author(s):  
Alessandro Piccolo ◽  
Riccardo Spaccini ◽  
Vincenza Cozzolino ◽  
Assunta Nuzzo ◽  
Marios Drosos ◽  
...  

2006 ◽  
Vol 10 (3) ◽  
pp. 309-320 ◽  
Author(s):  
M. Retter ◽  
P. Kienzler ◽  
P. F. Germann

Abstract. The focus is the experimental assessment of in-situ flow vectors in a hillslope soil. We selected a 100 m2 trenched hillslope study site. During prescribed sprinkling an obliquely installed TDR wave-guide provides for the velocity of the wetting front in its direction. A triplet of wave-guides mounted along the sides of an hypothetical tetrahedron, with its peak pointing down, produces a three-dimensional vector of the wetting front. The method is based on the passing of wetting fronts. We analysed 34 vectors along the hillslope at distributed locations and at soil depths from 11 cm (representing top soil) to 40 cm (close to bedrock interface). The mean values resulted as follows vx=16.1 mm min-1, vy=-0.2 mm min-1, and vz=11.9 mm min-1. The velocity vectors of the wetting fronts were generally gravity dominated and downslope orientated. Downslope direction (x-axis) dominated close to bedrock, whereas no preference between vertical and downslope direction was found in vectors close to the surface. The velocities along the contours (y-axis) varied widely. The Kruskal-Wallis tests indicated that the different upslope sprinkling areas had no influence on the orientation of the vectors. Vectors of volume flux density were also calculated for each triplet. The lateral velocities of the vector approach are compared with subsurface stromflow collected at the downhill end of the slope. Velocities were 25-140 times slower than lateral saturated tracer movements on top of the bedrock. Beside other points, we conclude that this method is restricted to non-complex substrate (skeleton or portion of big stones).


2010 ◽  
Vol 10 (18) ◽  
pp. 8881-8897 ◽  
Author(s):  
Y. Wang ◽  
J. W. Munger ◽  
S. Xu ◽  
M. B. McElroy ◽  
J. Hao ◽  
...  

Abstract. Although China has surpassed the United States as the world's largest carbon dioxide emitter, in situ measurements of atmospheric CO2 have been sparse in China. This paper analyzes hourly CO2 and its correlation with CO at Miyun, a rural site near Beijing, over a period of 51 months (Dec 2004 through Feb 2009). The CO2-CO correlation analysis evaluated separately for each hour of the day provides useful information with statistical significance even in the growing season. We found that the intercept, representing the initial condition imposed by global distribution of CO2 with influence of photosynthesis and respiration, exhibits diurnal cycles differing by season. The background CO2 (CO2,b) derived from Miyun observations is comparable to CO2 observed at a Mongolian background station to the northwest. Annual growth of overall mean CO2 at Miyun is estimated at 2.7 ppm yr−1 while that of CO2,b is only 1.7 ppm yr−1 similar to the mean growth rate at northern mid-latitude background stations. This suggests a relatively faster increase in the regional CO2 sources in China than the global average, consistent with bottom-up studies of CO2 emissions. For air masses with trajectories through the northern China boundary layer, mean winter CO2/CO correlation slopes (dCO2/dCO) increased by 2.8 ± 0.9 ppmv/ppmv or 11% from 2005–2006 to 2007–2008, with CO2 increasing by 1.8 ppmv. The increase in dCO2/dCO indicates improvement in overall combustion efficiency over northern China after winter 2007, attributed to pollution reduction measures associated with the 2008 Beijing Olympics. The observed CO2/CO ratio at Miyun is 25% higher than the bottom-up CO2/CO emission ratio, suggesting a contribution of respired CO2 from urban residents as well as agricultural soils and livestock in the observations and uncertainty in the emission estimates.


2019 ◽  
Vol 112 ◽  
pp. 03024 ◽  
Author(s):  
Nicolae Cioica ◽  
Cătălina Tudora ◽  
Dorin Iuga ◽  
György Deak ◽  
Monica Matei ◽  
...  

Heavy metals are among the most common types of contaminants in agricultural soils, especially those bordering the cities, due to the uncontrolled use of sewage sludge, compost, mining waste and chemical fertilizers. Excessive accumulation of heavy metals, which do not degrade over time, adversely affects crop yields by decreasing microbial activity and fertility of contaminated soils. Also, excess of heavy metals in the soil poses a serious threat to plant and animal health and, through their entry into the food chain, to human health. For this reason, the decontamination of soils contaminated with heavy metals has become a necessity. This review presents the current state of phytoremediation research as the most cost-effective method of in-situ environmental decontamination of soils contaminated with heavy metals.


2019 ◽  
pp. 1-13
Author(s):  
Chun Song ◽  
Clement Kyei Sarpong ◽  
Jinsong He ◽  
Fei Shen ◽  
Jing Zhang ◽  
...  

Agricultural activities and agro-inputs, particularly chemical fertilizers, farmyard manure, pesticide, sewage sludge, plastic mulch, irrigation, etc., are the primary source of pollutants in farmlands. Agricultural land degradation has become a major concern as it poses a threat to crop productivity. In recent years, microbial-assisted phytoremediation has gained much attention as a promising in situ remediation technology for cleaning polluted soils. Several beneficial rhizobacteria and endophytes facilitate phytoremediation by stimulating innate plant growth-promoting traits such as the production of siderophores, phytohormones, and chelators in addition to their ability to biodegrade contaminants and enhance their removal. Current studies on microbial mediated phytoremediation are demonstrating significant remediation potential. However, there are several challenges in the field that restrict the remediation process. Here we highlight the specific traits, mechanisms, roles, advantages, and problems associated with microbial-assisted phytoremediation.


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